Albizia myriophylla (PROSEA)
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Introduction |
Albizia myriophylla Benth.
- Protologue: Lond. Journ. Bot. 3: 90 (1844).
- Family: Leguminosae
- Chromosome number: 2n= unknown
Synonyms
Albizia thorelii Pierre (1899).
Vernacular names
- Malaysia: akar manis, akar kulit manis, tebu gajah (Peninsular)
- Cambodia: voë ‘a:èm, ph-‘a:èm, sâmbu:ër kâk’
- Laos: khua kha:ng hung¹ khuang
- Thailand: som poi wan (northern), cha-em thai (central), oi chang (peninsular)
- Vietnam: dây cam thảo nam (Tây Ninh), sống rắn (Dông Nai).
Origin and geographic distribution
A. myriophylla occurs from the Himalayas and India, through Burma (Myanmar), Indo-China (Cambodia, Laos and southern Vietnam) and Thailand, to northern Peninsular Malaysia.
Uses
In Malaysia an infusion of A. myriophylla roots is used internally against fever. A lotion made from the roots is used as a substitute for liquorice ( Glycyrrhiza glabra L.) and, in combination with other plants, is applied to the head for children with fever. A lotion prepared by boiling the leaves is applied to the head to treat earache. The bark is used in traditional medicine in Indo-China to treat bronchitis and cough, and the leaves are applied to wounds to stop bleeding. The bark is also used as a substitute for liquorice. In Thailand the root is used to alleviate thirst, and as a laxative and mucolytic, and the wood and fruit are used as an expectorant.
Properties
Stem and root bark of A. myriophylla have a sweet taste, but the quality of sweetness is different from that of glycyrrhizin (from liquorice) or sugars. Lignan glycosides (albizziosides A, B and C) have been isolated from the bark, but these do not taste sweet. A macrocyclic spermidine alkaloid was also isolated from the bark. It is striking that the bark is used for similar complaints as liquorice, such as against bronchitis and cough, although glycyrrhizin does not seem to be the active compound.
Saponins have been demonstrated in many Albizia species, including A. myriophylla ; they are accordingly often used as fish poison. Cytotoxic activity is reported for some species. An example is A. lebbeck (L.) Benth., of which the roots and fruits showed anticancer activity, as well as hypoglycaemic and antiprotozoal activity.
Botany
A scandent shrub or liana; branches armed with hook-like prickles. Leaves arranged spirally, stipulate, bipinnate with 8-20 pairs of pinnae, rachis and pinnae with extrafloral nectaries; leaflets opposite, 25-60 pairs per pinna, entire. Inflorescence consisting of pedunculate glomerules arranged into a terminal panicle. Flowers sessile, bisexual but the central flower in a glomerule male and enlarged, 5-merous; calyx funnel-shaped to campanulate; corolla funnel-shaped, 3.5-5.5 mm long; stamens numerous, united into a tube, white; ovary superior, stipitate. Fruit an oblong, flat pod, c. 14 cm × 2.5 cm. Seeds orbicular to obovoid, with distinct pleurogram; cotyledons thick, endosperm absent.
Albizia comprises about 150 species and has a pantropical distribution, with centres of speciation in Africa, Madagascar and tropical America. It occurs throughout the Asian tropics and 20 species are indigenous within the Malesian region. Most species have a tree habit; however, few are armed lianas like A. myriophylla , and are often confused with lianescent Acacia species, but can be distinguished by the stems which are armed by a single, recurved prickle from the base of the leaf-scar (stems armed with prickles at the internodes or paired just below the internodes in Acacia ), and by the united stamens (more or less free in Acacia ).
Ecology
A. myriophylla occurs in a wide range of lowland habitats, often in forest margins, on sandy river banks and in disturbed habitats, up to 300 m altitude in Malaysia, up to 900 m in Indo-China and Thailand.
Genetic resources
Although A. myriophylla has a limited distribution in Malesia, it is widespread and not uncommon in Indo-China and Thailand. It does not seem easily liable to genetic erosion, the more so because it also occurs in secondary habitats and is not much collected.
Prospects
Information on pharmacological activities of A. myriophylla is lacking and research is needed to judge its potential importance. The sweetening properties might be of commercial interest, but the identity and safety of the compounds responsible should be determined.
Literature
160, 247, 399, 400.
Other selected sources
121, 249, 250, 671.
Main genus page
Authors
R.H.M.J. Lemmens
